1. Field of the Invention
The present invention relates to production of phycocolloid and fertilizer from fresh seaweeds.
Specifically, the invention relates to preparation of κ-carrageenan and liquid fertilizer from fresh Kappaphycus alvarezii (also known as Eucheuma striatum or Eucheuma cottonii or very simply as Eucheuma) in a manner that allows integrated recovery of two products from the seaweed simultaneously with other accompanying benefits so as to maximize the returns from cultivation of the seaweed.
2. Background and Prior Art References
κ-Carrageenan is used as a thickening agent in numerous applications such as pet food, fruit jam, toothpaste, and ice cream. The red seaweed, Kappaphycus alvarezii, which grows in tropical waters, is cultivated extensively in countries such as the Philippines and Indonesia as a source of κ-carrageenan. J. G. Lewis, N. F. Stanley and G. G. Guist, in the book, Algae and Human Affairs, C. A. Lembi and J. R. Waaland, Eds., Cambridge University Press, Cambridge, 1990; pp. 218), have reviewed the diverse applications of refined and semi-refined κ-carrageenan. G. H. Thirkelsen (in: Industrial Gums—Polysaccharides and their Derivatives, R. L. Whistler and J. N. BeMiller, Eds., 3rd Edition, Academic Press Inc., New York, 1993, pp 145-180) has also described the diverse applications of carrageenan.
V. J. Chapman and D. J. Chapman have reported in their book, Seaweeds and their Uses, (Chapman and Hall, London & New York, 1980; Chapter 2, pp 30-61) that several seaweed extracts are useful as foliar spray for improved plant growth.
G. Blunden (in: Marine Natural Products Chemistry, D. J. Faulkner and W. H. Fenical, Eds., Plenum Press, New York, 1977; pp. 337-344) has provided evidence of cytokinin activity of seaweed extracts while F. C. Sumera and G. J. B. Cjipe (in: Botanica Marina, Vol. 24, 157-163, 1981) have reported auxin-like substances in the extracts of Sargassum polycystum. B. Metting, W. R. Rayburn and P. A. Raynand (in: Algae and Human Affairs, C. A. Lembi and J. R. Waaland, Eds., Cambridge University Press, Cambridge, 1990; pp. 357-370) have reported that many seaweeds contain plant growth regulators such as auxins, gibberellins, abscisic acid and quaternary ammonium compounds.
The red seaweed Kappaphycus alvarezii is known as a source of refined and semi-refined κ-carrageenans. Eucheuma preparation is also used as foliar spray to enhance flowering and growth of crop. Conventionally, all seaweeds, including Eucheuma, are dried at the harvesting location and baled for shipment to processing plants as described by V. J. Chapman and D. J. Chapman in their book, Seaweeds and their Uses (Chapman and Hall, London & New York, 1980; Chapter 2, pp 30-61). In most collection areas, sun-drying remains the most cost-effective technique, although oil-fired mechanical dryers are used to a limited extent. The dry seaweed is used mainly for preparation of phycocolloids. Some factories are dedicated to production of seaweed fertilizer. At the cottage industry level—such as in certain coastal villages of India—freshly harvested seaweed is boiled in earthen pots, the liquid extract utilised as fertilizer and the solid residue is either discarded or used as manure.
Reference may be made to Alphons C. J. Voragen, Walter Pilnik, Claus Rolin, Beinta U. Marr, Ian Challen, Abdel Wahab Riad and Rachid Lebbar in Polysaccharides-Carrageenan (Ullmann's Encyclopedia of Industrial Chemistry, Sixth Edition, 2002 Electronic Release) wherein production of κ-carrageenan from Eucheuma cottonii (Kappaphycus alvarezii) is described as follows: “After being harvested, the algae are washed and dried to a dry matter content of ca. 25 wt. %; . . . The dried algae are treated with alkali and ground to a paste. Alkaline conditions facilitate extraction of the macerated algae.” It can be seen that the present practice is to dry the harvested algae and subsequently utilize this dried algae for production of κ-carrageenan. There is no reference to recovery of any liquid fertilizer or second product prior to drying of the harvested seaweed nor is there any mention of any method other than drying for removing water from the fresh algae.
Reference may be made to S. Craigie and C. Leigh (in: Handbook of Phycological Methods, Hellebust, J A and Craigie J S., Eds., Cambridge University Press, London, 1978; pp.112) who have reported that red seaweed is used in frozen-fresh condition for extraction of refined carrageenan. However, the authors have not reported the preparation of any fertilizer from the same seaweed.
Reference may be made to Q. Hurtado-Ponce (Botanica Marina 38:137, 1995) who has reported that Kappaphycus alvarezii (more popularly known as Eucheuma) seaweed was harvested, washed and sun/oven dried for recovery of carrageenan. No reference is made to recovery of fertilizer from the same plant.
Reference may be made to G. Lewis, N. F. Stanley and G. G. Guist, (in Algae and Human Affairs, C. A. Lembi and J R Waaland, Eds.,Cambridge University Press, Cambridge, 1990; pp. 218) who have reported the extraction of carrageenan by drying of the fresh red sea weed after harvesting. No reference is made to simultaneous recovery of any fertilizer.
C. J. Dawes, N. F. Stanley and D. J. Stancioff (Botanica Marina, Vol XX, 1977, Fasc. 3) have also reported that seaweeds are dried in the sun and subsequently utilised for extraction of carrageenan. No mention is made of recovery of fertilizer from the same plant.
P. M. Alino, G. J. B. Cajipe, E. T. Ganzon-Fortes, W. R. Y. Licuanan, N. E. Montano, and L. M. Tupas (in: The use of marine organisms in folk medicine and horticulture : A preliminary study, SICEN Leaflet 1. Supplement of SICEN Newsletter, published by Seaweed Information Center (SICEN), Marine Science Institute, University of Philippines, Dilman, Quezon City, Philippines, February 1990), have reported that Eucheuma decoction is used as foliar spray to enhance flowering and growth of crops. However there is no mention of simultaneous recovery of carrageenan from the same seaweed.
L. Tupas and N. E. Montano (in: Philipp. J. Sci., Monograph No. 17, pp 29-35, 1987) have reported the effects of alkaline extracts from Philippine seaweeds as foliar spray on crops. No mention is made of simultaneous recovery of carrageenan from the seaweed.
It is known to those practising the art that effluent generated after recovery of phycocolloids from different seaweeds can be utilised as fertilizer after suitable treatment. It is also known that the harsh conditions under which seaweeds are normally processed for phycocolloid extraction can be detrimental to the growth promoting substances present in the seaweed.
It is also know to those involved in seaweed cultivation that drying of seaweed after harvesting is an involved affair and any savings in the area or time required for drying would be advantageous.
It is also known to those involved in seaweed cultivation and downstream processing that dry seaweeds are bulky and, therefore, costly to transport and store, and any savings in the above would be advantageous.